I Checked the documentation and tried to search forum before asking.
in documentation (http://wtware.com/docs5/config.html) and configurator it says:
"This line means that terminal will be trying to connect to server for 15 seconds. Only after that it reports that server is unavailable. May be usefull for slow and unreliable channels."

I tested 5.6.25 and it works fantastic, also in the configurator the explanation now makes sense:

"This line means that terminal will be trying to connect to server for at least 5 seconds and no more than 60 seconds."